Process for the manufacture of alkylamino alkylene phosphonic acids

ABSTRACT

A process for the manufacture of alkylamino alkylene phosphonic acids is disclosed. In detail, a specific phosphonate is reacted with an agent selected to yield an alkylamino moiety substituted by a radical selected from OH, OR&#39;, NH 2 , NHR′, N(R′) 2 , NH, N, S, S—S and SH in aqueous alkaline medium having a pH of 8 or higher at a temperature of 0° C. or higher.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 12/518,663 filed on Mar. 11, 2010, which claims the benefit ofpriority from International Application PCT Application No.PCT/EP2007/063682 filed on Dec. 11, 2007 and European Patent ApplicationNo. EP 06025514.8 filed on Dec. 11, 2006. The disclosures ofInternational Application PCT Application No. PCT/EP2007/063682 andEuropean Patent Application No. EP 06025514.8 are incorporated herein byreference.

BACKGROUND OF THE INVENTION

This invention concerns a process for the manufacture of alkylaminoalkylene phosphonic acids wherein the aminoalkyl moiety is substitutedby a radical selected from OH, OR′, N, NH, NH₂, NHR′, N(R)₂, S, HS, andS—S. To that effect, a specific phosphonate starting reagent is reactedwith the precursor of the selected radical in aqueous alkaline mediumhaving a pH of 8 or higher at a temperature of 0° C. or higher.

Alkylamino alkylene phosphonic acids are well known and have foundapplication in reducing scale formation in aqueous systems broadly, inparticular in oil field operations in which the formation water, whichis usually discharged with the oil at the well head, contains frequentlyhigh concentrations of alkaline earth metal and consequently exhibitshigh scale formation potential. GB 2 306 465 describes a method oftreating water to inhibit barium scale deposition by adding a thresholdlevel of an inhibitor mixture containing about equal parts of analkanolamino bis (alkylene phosphonic acid) and intermolecular cyclicphosphonate which has been shown to be ineffective for scale inhibitionpurposes in aqueous medium. The mixture of the alkanolamine bis(alkylene phosphonic acid), having scale control properties, and theinert, in relation to scale control, intermolecular cyclic phosphonateare prepared in a typical manner by reacting the requisite startingmaterials, namely formaldehyde, phosphorous acid and a hydroxyalkylamineor a hydroxyalkyl alkyleneamine in the presence of a mineral acidcatalyst. WO 2000/0018695 discloses a method for converting mixtures ofthe closed (inactive) phosphonates and open (active) phosphonates toring-opened bis (methylene phosphonates) by submitting the mixture to aprolonged boiling treatment at a high pH equal to or higher than 12.

U.S. Pat. No. 4,330,487 describes a process of preparingN,N′-disubstituted methylene phosphonic acids by reacting α,ω-alkylenediamines with formaldehyde and phosphorous acid in aqueous medium inaccordance with the Mannich reaction at a pH of generally less than 1.Zaitsev V. N. et al., Russian Chemical Bulletin, (1999), 48(12),2315-2320, divulges modified silicas containing aminophosphonic acidscovalently bonded onto the silica surface.

DE 31 287 55 discloses 3-alkoxypropyleneimino bis (methylene phosphonicacids) wherein the alkyl moiety can contain from 2 to 20 carbon atoms, aprocess for the manufacture of the phosphonic acid compounds and the usethereof in the flotation of non-sulfide ores. The compounds are producedby reacting an alkoxypropylene amine with formaldehyde and phosphorousacid at a reaction mixture pH below 4, more suitably below 2 in order toobtain optimum results. Suitable acidifying agents include hydrochloricacid, hydrobromic acid, sulfuric acid, phosphoric acid and sulfonicacids.

U.S. Pat. No. 3,974,090 describes iminoalkylimino phosphonates and amethod for the preparation thereof. To that effect, phosphorous acid,formaldehyde and an amine are reacted in an acid medium in aconventional manner. U.S. Pat. No. 4,477,390 discloses aminomethylenephosphonic acid solutions prepared and stabilized under acid conditions.The triamine tetra (methylene phosphonic acid) compound is formed in alevel of 2%. Yoshiro Yokoyama, Bull. Chem. Soc. Jpn., 58, 3271-3276(1985), pertains to chelating phosphonate resins, prepared in aconventional manner, under acid conditions. U.S. Pat. No. 3,705,005pertains to aminoalkylene phosphonate derivatives such as bis(aminoethyl) sulphide tetra (methylene phosphonic acid). The lattercompound is prepared in acid medium in a fairly conventional manner U.S.Pat. No. 4,234,511 relates to aminoalkylene phosphonates such as e.g.the formation of N,N (dimethylamino) -bis (phosphonomethyl) propylaminehydrochloride starting from dimethylamino propylamine Sulfur containingmethylene phosphonic acids are known from Razumovskii N. O et al.,Deposited Doc. (1984), (VINITI 1784-84), 8 pp.

Significant R&D efforts expanded have not yielded remedy to prior artmanufacturing shortcomings. As an example, di-phosphonate scaleinhibitors do not offer, at least in part due to the presence ofexcessive levels of substantially inert, with respect to scale control,phosphonates such as cyclic phosphonates, a viable approach foreffective commercial practice.

BRIEF DESCRIPTION OF THE INVENTION

It is a main object of this invention to provide a process for themanufacture of alkylamino, particularly poly (alkylene phosphonicacids), preferably bis (alkylene phosphonic acids), containingsubstantially reduced levels of inert, in relation to e.g. watertreatment, reaction products. It is another object of this invention toprovide improved, substantially one- step, manufacturing technology forselected alkylene phosphonic acids without the occurrence of undueby-product negatives. Still another object of this invention aims atstreamlining the phosphonic acid manufacturing technology by requiring asimplified sequence e.g. without a need for time-consuming correctivehydrolysing steps. Still another aim of the technology herein seeks togenerate highly active water treatment agents, such as e.g. can beuseful in relation to scale control broadly. Still another object of theinvention aims at providing a simplified arrangement for synthesizingphosphonate derivatives.

The foregoing and other objectives can now be met by means of amanufacturing arrangement, as set forth in more detail below, byreacting, in aqueous medium having a substantially alkaline pH, aspecifically defined reactive phosphonate with a non-phosphonatereactant.

The term “percent” or “%” as used throughout this application stands,unless defined differently, for “percent by weight” or “% by weight”.The terms “phosphonic acid” and “phosphonate” are also usedinterchangeably depending, of course, upon medium prevailingalkalinity/acidity conditions.

DETAILED DESCRIPTION OF THE INVENTION

A process for the beneficial manufacture of alkylene phosphonic acidshas now been discovered. In more detail, the inventive arrangement aimsat the preparation of phosphonic acids having the formula:

U—[X—N (W) (ZPO₃M₂)]_(s)

by reacting a phosphonic acid compound having the formula:

Y—X—N (W) (ZPO₃M₂)

with a precursor of the moiety:

U

the structural elements having the following meaning:

Y is selected from substituents the conjugated acid of which has a pKaequal to or smaller than 4.0;

X is selected from C₂-O₅₀ linear, branched, cyclic or aromatichydrocarbon chain, optionally substituted by a C₁-C₁₂ linear, branched,cyclic, or aromatic group, (which chain and/or which group can be)optionally substituted by OH, COOH, F, OR′, R₂O[A-O]_(x)-wherein R² is aC₁-O₅₀ linear, branched, cyclic or aromatic hydrocarbon chain and SR′moieties, wherein R′ is a C₁-O₅₀ linear, branched, cyclic or aromatichydrocarbon chain, optionally substituted by C₁-C₁₂ linear, branched,cyclic or aromatic hydrocarbon groups, (said chains and/or groups canbe) optionally substituted by COOH, OH, F, OR′, SR and [A-O]_(x)-Awherein A is a C₂-C₉ linear, branched, cyclic or aromatic hydrocarbonchain and x is an integer from 1 to 200;

Z is a C₁-C₆ alkylene chain;

M is selected from H and C₁-C₂₀ linear, branched, cyclic or aromatichydrocarbon chains;

W is selected from H, ZPO₃M₂ and [V-N (K)]_(n)K, wherein V is selectedfrom: a C₂-C₅₀ linear, branched, cyclic or aromatic hydrocarbon chain,optionally substituted by C₁-C₁₂ linear, branched, cyclic or aromaticgroups, (which chains and/or groups can be) optionally substituted byOH, COOH, F, OR′, R²O[A-O]_(x)-wherein R² is a C₁-C₅₀ linear, branched,cyclic or aromatic hydrocarbon chain, or SR′ moieties; and from[A-O]_(x)-A wherein A is a C₂-C₉ linear, branched, cyclic or aromatichydrocarbon chain and x is an integer from 1 to 200;

K is ZPO₃M₂ or H and n is an integer from 0 to 200; and

U is a moiety selected from NH₂, NHR', N(R′)₂, NH, N, OH, OR′, S, HS andS—S wherein R′ is as defined above;

s is 1 in the event U stands for NH₂, NHR′, N(R′)₂, OR′, HS or

OH; s is 2 in the event U stands for NH, S or S—S; and s is 3 in theevent U stands for N; in aqueous medium, having a pH of 8 or more, at atemperature of 0° C. or higher.

Y in the phosphonate starting compound represents a substituent theconjugated acid of which has a pKa equal to or smaller than 4.0,preferably equal to or smaller than 1.0.

The pKa value is a well-known variable which can be expressed asfollows:

pKa=−log₁₀ Ka.

wherein Ka represents the thermodynamic equilibrium acidity constant.The pKa values of all acid substances are known from the literature orcan, if this were needed, be determined conveniently. Values are listed,e.g., in the Handbook of Chemistry and Physics.

Y can preferably be selected from Cl, Br, I, HSO₄, NO₃, CH₃SO₃ andp-toluene sulfonate and mixtures thereof.

In the definition of X, R², R′, A and V the C_(x)-C_(y) linear orbranched hydrocarbon chain is preferably a linear or branchedalkane-diyl with a respective chain length. Cyclic hydrocarbon chain ispreferably C₃-C₁₀-cycloalkane-diyl. Aromatic hydrocarbon chain ispreferably C₆-C₁₂-arene-diyl. When the foregoing hydrocarbon chains aresubstituted, it is preferably with linear or branched alkyl of arespective chain length, C3-C₁₀-cycloalkyl, or C₆-C₁₂-aryl. All thesegroups can be further substituted with the groups listed with therespective symbols.

More and particularly preferred chain lengths for alkane moieties arelisted with the specific symbols. A cyclic moiety is more preferred acyclohexane moiety, in case of cyclohexane-diyl in particular acyclohexane-1,4-diyl moiety. An aromatic moiety is preferably phenyleneor phenyl as the case may be, for phenylene 1,4-phenylene isparticularly preferred.

The individual moieties in the phosphonate reaction partner can, in apreferred manner, be beneficially selected from species as follows:

Moiety Preferred Most Preferred X C₂-C₃₀ C₂-C₁₂ [A—O]_(x)—A [A—O]_(x)—AV C₂-C₃₀ C₂-C₁₂ [A—O]_(x)—A [A—O]_(x)—Awherein for both, X and V independently:

A C₂-C₆ C₂-C₄ x 1-100 1-100 Z C₁-C₃ C₁ M H, C₁-C₆ H, C₁-C₄ n 1-100 1-25R² C₁-C₃₀ C₁-C₁₂

The U moieties can be obtained from well-known precursors, readilyavailable in the domain of the technology, which can be reacted with thereactive phosphonic acid compound. Examples of preferred precursors forthe individual U moieties are as follows:

Precursor U Moiety NH₃ NH₂ NH₂R″ NHR″ NH(R′)₂ N(R′)₂ NH₃ NH NH₃ N OH⁻ OHHOR″; R″O OR″ Na₂S S Thiourea SH Na₂S₂ S—S

The R′ substituents in the N(R′)₂ moiety can be identical or different.

The phosphonate compounds herein can be synthesized by means ofconventional measures routinely available in the relevant domain.

In one approach, the reactive phosphonate starting material and areaction partner being a precursor of the U moiety are usually combined,in an aqueous medium, by adding stoichiometric proportions of thespecies, thereby taking into consideration controllable variables suchas the required degree of substitution. The reaction is carried outunder alkaline conditions, generally at a pH of 8 or more, preferably ata pH in the range of from 9-14. The pH is measured in the reactionmedium, as is, at the reaction temperature. The reaction temperature isgenerally above 0° C., usually in the range of from 10° C. to 120° C.Higher reaction temperatures can be used subject to adequate pressurecontainment e.g. by means of standard pressure vessels.

Recovery of the reaction products is preferably carried out in a mannerknown per se to those skilled in the art. For example, the freephosphonic acids can be precipitated by acidification of the reactionmixture, e. g. with concentrated hydrochloric acid, filtered of, washedand dried. Further purification can, e.g., be effected byrecrystallisation or chromatographic methods.

The phosphonates obtained by the process of the invention are preferablyused in the chemical and pharmaceutical industry, the textile industry,the oil industry, paper industry, sugar industry, beer industry, theagrochemical industry and in agriculture.

Preferred uses are as dispersants, water treatment agents, scaleinhibitors, pharmaceuticals and pharmaceutical intermediates,detergents, secondary oil recovery agents, fertilizers andmicronutrients (for plants).

EXAMPLES

Examples I-XIV, which relate to the manufacturing technology of thisinvention, were prepared as follows.

I:

111.48 g (0.4 mole) of 96% pure 2-chloro ethyl imino bis (methylenephosphonic acid) (CEIBMPA) were mixed under stirring with 300 ml ofwater. 30 g of a 50% aqueous solution of sodium hydroxide (0.375 mole)was diluted with water to 100 ml and added, under stirring below 10° C.,to the CEIBMPA aqueous solution. This mixture was then added over aperiod of 160 minutes to 162 g (2.025 moles) of 50% sodium hydroxideunder good stirring at a temperature between 95° C. and 100° C. Heatingwas further continued for 60 minutes at 100° C. ³¹P NMR of the crudereaction product showed the presence of 88.3% of the hydroxyl homologueof CEIBMPA; the corresponding cyclic phosphonate ester is absent fromthe crude product.

II:

55.74 g (0.2 mole) of 96% pure 2-chloro ethyl imino bis (methylenephosphonic acid) were mixed, under stirring at 10° C., with 75 ml ofwater. To this suspension was added, under stirring between 6° C. and 8°C., a solution of 15 g (0.1875 mole) of 50% sodium hydroxide dilutedwith water to a volume of 60 ml. This mixture was further diluted withwater to a total volume of 200 ml (solution 1). 49 g (0.6125 mole) of50% sodium hydroxide was diluted with water to a volume of 75 ml(solution 2). Solutions 1 and 2 were added to 59.11 g (1 mole) ofn-propylamine, diluted in 100 ml of water, under stirring at 40° C. overa period of 70 minutes. ³¹P NMR of the reaction product showed thepresence of 81.6% of the phosphonic acid, N-n-propyl ethylene diamineN′,N′-bis (methylene phosphonic acid), 6.8% of hydroxy (ethyl bis(methylene phosphonic acid)) and 11.6% of N-n-propyl bis (ethylenediamine N′,N′-bis(methylene phosphonic acid)).

III:

55.72 g (0.2 mole) of 96% pure 2-chloro ethyl imino bis (methylenephosphonic acid) were mixed, under stirring at 10° C., with 150 ml ofwater. To this suspension was added, under stirring between 6° C. and 8°C., a solution of 15 g (0.1875 mole) of 50% sodium hydroxide dilutedwith water to a volume of 50 g. This solution was added, at roomtemperature under stirring, to 272 g (4 moles) of a 25% ammonia solutionin 120 minutes followed by heating this mixture at 95° C. for 180minutes. ³¹P NMR of the reaction product showed the presence of 95% ofamino ethyl imino bis (methylene phosphonic acid) and 5% of2-hydroxyethyl imino bis (methylene phosphonic acid) (HOEIBMPA).

IV:

111.48 g (0.4 mole) of 96% pure 2-chloro ethyl imino bis (methylenephosphonic acid) were mixed, under stirring at 10° C., with 150 ml ofwater. To this suspension was added, under stirring between 6° C. and 8°C., a solution of 30 g (0.375 mole) of 50% sodium hydroxide diluted withwater to a volume of 100 ml (solution 1). 138 g (1.725 moles) of sodiumhydroxide were diluted with water to 250 ml (solution 2). Solutions 1and 2 were added, between 6° C. and 8° C., under stirring to 13.6 g (0.2mole) of a 25% ammonia solution in 135 minutes followed by heating themixture at 95° C. for 240 minutes. ³¹P NMR of the reaction productshowed the presence of 38.5% of 2-amino ethyl imino bis (methylenephosphonic acid); 32.5% of imino bis [ethyl imino bis (methylenephosphonic acid)] and 8% of the 2-hydroxy EIBMPA.

V:

111.48 g (0.4 mole) of 96% pure 2-chloro ethyl imino bis (methylenephosphonic acid) were mixed under stirring at 10° C. with 300 ml ofwater. To this suspension was added under stirring between 6° C. and 8°C. a solution of 30 g (0.375 mole) of 50% sodium hydroxide diluted withwater to a volume of 100 ml (solution 1). 130 g (1.625 mole) of 50%sodium hydroxide were diluted with water to 250 ml (solution 2).

Solutions 1 and 2 were added, between 6° C. and 8° C. under stirring, to54.4 g (0.8 mole) of a 25% ammonia solution in 180 minutes followed byheating the mixture between 60° C. and 80° C. for 300 minutes. ³¹P NMRof the reaction product showed the presence of 22% of 2- amino ethylimino bis (methylene phosphonic acid); 56.2% of imino bis [ethyl iminobis (methylene phosphonic acid)]; 11.8% of the nitrilo tris [ethyl iminobis (methylene phosphonic acid)] and 9.8% of hydroxy EIBMPA.

VI:

55.72 g (0.2 mole) of 96% pure 2-chloro ethyl imino bis (methylenephosphonic acid) were mixed under stirring at 10° C. with 150 ml ofwater. To this suspension was added, under stirring between 6° C. and 8°C., a solution of 15 g (0.1875 mole) of 50% sodium hydroxide dilutedwith water to volume of 50 ml (solution 1). 97 g (1.2125 moles) of 50%sodium hydroxide were diluted with water to 120 ml (solution 2).

Solutions 1 and 2 were added at room temperature under stirring to 4.56g (0.067 mole) of a 25% ammonia solution in 150 minutes followed byheating at 95° C. for 240 minutes. ³¹P NMR of the reaction productshowed the presence of 19.9% of imino bis [ethyl imino bis (methylenephosphonic acid)]; 76.3% of nitrilo tris [ethyl imino bis (methylenephosphonic acid)] and 3.8% of hydroxy EIBMPA.

VII Comparative:

20.44 g of n-propyl ethylene diamine (0.2 mole) were mixed with 32.8 g(0.4 mole) of phosphorous acid and 59.12 g (0.6 mole) of a 37% aqueousHC1 solution. The solution was heated at 107° C. under stirring and36.10 g (0.44 mole) of a 36.6% aqueous formaldehyde solution were addedin 25 minutes. Heating was continued further for 120 minutes at 107° C.³¹P NMR analysis of the reaction product showed the presence of 37.2% ofn-propyl ethylene diamine tri (methylene phosphonic acid); 28% of theN-n-propyl N-methylene phosphonic acid ethylene diamine; 10.6% of theN-n-propyl ethylene diamine N′,N′-bis (methylene phosphonic acid) aswell as 11.6% of unconverted phosphorous acid.

VIII Comparative:

Reaction of ethylene diamine with phosphorous acid, formaldehyde in thepresence of HCl in accordance with D. Redmore et al. in Phosphorus andSulfur, 1983, Vol 16, pp 233-238.

30 g (0.5 mole) of ethylene diamine were mixed with 82 g (1 mole) ofphosphorous acid, 250 ml of water and 250 ml (2.69 moles) of 37% aqueousHCl. This solution was heated under stirring to 110° C. and 90.25 g (1.1mole) of 36.6% aqueous formaldehyde solution were added in 60 minutes.Heating was continued at 110° C. for 120 minutes. ³¹P NMR analysis ofthe reaction product showed the presence of 25.2% of ethylene diaminetetra (methylene phosphonic acid); 48.4% of 2-amino ethyl imino bis(methylene phosphonic acid); 10.1% of ethylene diamine tri (methylenephosphonic acid) and 4.7% of N-methyl ethylene diamine tri (methylenephosphonic acid) as major constituents.

IX:

38.86 g (0.4 mole) of diallylamine were mixed with 200 ml of ethanol and100 ml of water. 111.48 g (0.4 mole) of 96% pure 2-chloro ethyl iminobis (methylene phosphonic acid) were mixed with 150 g of water and 30 g(0.375 mole) of 50% sodium hydroxide itself diluted with water to avolume of 120 ml at 10° C. (Solution 1). 98 g (1.225 moles) of 50%sodium hydroxide were diluted with water to 150 ml (Solution 2).

Solutions 1 and 2 were added to the diallylamine solution under stirringat 70° C.-75° C. Heating was continued at 75° C. for 3 hours. ³¹P NMRanalysis of the reaction product showed 63% of diallylamine mono-ethyl2-imino bis (methylene phosphonic acid) and 10% of 2-hydroxy ethyl iminobis (methylene phosphonic acid).

X:

58.66 g (0.2 mole) of 96% pure 3-chloro propyl imino bis (methylenephosphonic acid) were mixed under stirring at 10° C. with 100 ml ofwater. To this suspension was added under stirring between 6° C. and 8°C. a solution of 32 g (0.4 mole) of 50% sodium hydroxide diluted withwater to a volume of 100 ml. 18.8 g (0.2 mole) of phenol were mixed with100 ml of water and 32 g (0.4 mole) of 50% aqueous sodium hydroxide.This solution was added to the 3-chloro propyl imino bis (methylenephosphonic acid) solution at 8° C. 24 g (0.3 mole) of 50% sodiumhydroxide diluted with water to 50 ml were further added to the reactionmixture at 8° C. and the resulting mixture was heated at 100° C. for 6hours. At room temperature, 80 ml of concentrated hydrochloric acid wereadded which resulted in the formation of a white precipitate collectedby filtration. After washing and drying a white powder (44.08 g or 65%yield) was obtained. 31P NMR of this product showed 98% of the 3-phenoxypropyl bis (methylene phosphonic acid).

XI:

26.41 g (0.2 mole) of sodium sulfide trihydrate were dissolved in 70 mlof water. 58.65 g (0.2 mole) of 96% pure 3-chloro propyl imino bis(methylene phosphonic acid) were mixed with 100 ml of water and 16 g(0.2 mole) of 50% sodium hydroxide at 10° C. under stirring (Solution1). 44 g (0.55 mole) of 50% sodium hydroxide were diluted with water toa volume of 70 ml (Solution 2). Solutions 1 and 2 were added to thesodium sulfide solution with good stirring at 70° C. and heating wasextended for 3 hours after complete addition. ³¹P NMR analysis of thereaction product showed 89% of the di [propyl 3-imino bis (methylenephosphonic acid)] sulfide and 11% of the corresponding thiol.

XII:

26.41 g (0.2 mole) of sodium sulfide trihydrate were dissolved in 70 mlof water. 55.7 g (0.2 mole) of 2-chloro ethyl imino bis (methylenephosphonic acid) were mixed with 75 ml of water and 15 g (0.1875 mole)of 50% sodium hydroxide at 10° C. under stirring (Solution 1). 49 g(0.6125 mole) of 50% sodium hydroxide were diluted with water to avolume of 100 ml (Solution 2). Solutions 1 and 2 were added to thesodium sulfide solution with good stirring at 10° C. The reactionmixture was then heated under stirring at 80° C. for 4 hours. ³¹P NMRanalysis of the reaction product showed 88% of the di [ethyl 2-imino bis(methylene phosphonic acid)] sulfide and 12% of the corresponding2-hydroxy ethyl imino bis (methylene phosphonic acid).

XIII:

58.66 g (0.2 mole) of 96% pure 3-chloro propyl imino bis (methylenephosphonic acid) were mixed under stirring at 10° C. with 100 ml ofwater. To this suspension was added under stirring at 10° C. a solutionof 16 g (0.2 mole) of 50% sodium hydroxide diluted with water to avolume of 60 ml (Solution 1). A sodium disulfide solution was preparedfrom 26.41 g (0.2 mole) of sodium sulfide trihydrate mixed understirring with 6.4 g (0.2 mole) of sulfur in 100 ml of water tillcomplete sulfur dissolution. 44 g (0.55 mole) of 50% sodium hydroxidewere diluted with water to a volume of 70 ml (Solution 2). Solutions 1and 2 were added to the disulfide solution under stirring at roomtemperature followed by heating at 95° C. for 3 hours. ³¹P NMR of thereaction mixture showed 58% of the di [propyl imino bis (methylenephosphonic acid)] disulfide; 20% of the corresponding mono-sulfide and9% of the hydroxy propyl imino bis (methylene phosphonic acid).

XIV:

58.66 g (0.2 mole) of 96% pure 3-chloro propyl imino bis (methylenephosphonic acid) were mixed under stirring at 10° C. with 100 ml ofwater. To this suspension was added under stirring at 10° C. a solutionof 32 g (0.4 mole) of 50% sodium hydroxide diluted with water to avolume of 100 ml (Solution 1). 15.22 g (0.2 mole) of thiourea were mixedwith 50 ml of water (Solution 2). Solution 2 was added to solution 1under stirring at 10° C. After completion of the addition 16 g (0.2mole) of 50% sodium hydroxide diluted with water to a volume of 60 mlwere added at 10° C. under stirring. The reaction mixture was heated at95° C. for 7 hours. 32 g (0.4 mole) of 50% sodium hydroxide were thenadded at room temperature and the reaction mixture heated at 100° C.under stirring for 2 hours. ³¹P NMR of the reaction mixture showed 53%of propyl imino bis (methylene phosphonic acid) sodium thiolate; 17% ofdi [propyl imino bis (methylene phosphonic acid)] sulfide and 16% ofhydroxy propyl imino bis (methylene phosphonic acid).

These testing data confirm the major benefits attached to the inventivetechnology as compared to the prevailing state of the art. Inparticular: Example I shows that, contrary to the GB 2 306 465arrangement, the inventive technology yields a reaction productsubstantially devoid of cyclic phosphonates which are ineffective fore.g. water treatment applications. Example II of the invention vs.comparative Example VII highlights the selectivity towards desirablespecies such as n-propyl amine ethyl imino bis (methylene phosphonicacid): Ex. II—81.6%, Ex. VII—10.6%. Example III of the invention yields95% of amino ethyl imino bis (methylene phosphonic acid) as compared to48.4% of the same compound in comparative Example VIII. Example IV showsthe formation of 38.5% of an amino compound together with 32.5% of acompound having the primary amine fully methylene phosphonated whilepreserving the unsubstituted secondary amino group. Such mixtures couldnot be synthesized by known methods. The observations formulated inrelation to Example IV are equally applicable to Example V yielding56.2% of a compound carrying an unreacted secondary amine and a fullymethylene phosphonated primary amine. This product could not beprepared, to any meaningful extent, by means of conventional methods. Inthis respect, Examples 1-34 of U.S. Pat. No. 4,477,390 illustrate theformation, in levels of 2%, vs. 56.2% in Example V of this invention, ofthe unreacted secondary amine. The inventive data are equally unexpectedin comparison to the testing data of U.S. Pat. No. 3,974,090. Example IIof the '090 patent highlights the predominant conversion to completelyphosphonated species as compared to 56.2% of an unreacted secondaryamine in Example V of this invention. Along the same lines, Example VIof this invention shows the formation of 76.3% of theaminotrisphosphonic compound as compared to 49% in accordance withExample I of the '090 art. In addition, the inventive technology allowsthe easy grafting of derivatives as compared to the cumbersomeapproaches of the art starting from presynthesized amines.

Example IX illustrates the possibility of preparing, with high yields, abis (methylene phosphonic acid) ethylene diamine whereby the secondnitrogen carries two allyl (R′) substituents. Using traditionaltechnology, this synthesis would require starting from N,N-di (allyl)ethylene diamine which is difficult and expensive to so prepare.Examples X through XIV concern the syntheses of various derivatives inhigh yields. Comparable to Example IX, these methods demonstrate theversatility of the claimed method vs. what can be made starting from artestablished linear approaches.

1. A process for the manufacture of alkylamino alkylene phosphonic acidshaving the formula:U—[X—N (W) (ZPO₃M₂)]_(s) by reacting a phosphonic acid compound havingthe formula:Y—X—N(W) (ZPO₃M₂) with a precursor of the moiety: U the structuralelements having the following meaning: Y is selected from: substituentsthe conjugated acid of which have a pKa equal to or smaller than 4.0; Xis selected from C₂-C₅₀ linear, branched, cyclic or aromatic hydrocarbonchains, optionally substituted by a C₁-C₁₂ linear, branched, cyclic, oraromatic group, (which chain and/or which group can be) optionallysubstituted by COOH, F, R²0 [A-O]_(x)-wherein R² is a C₁-C₅₀ linear,branched, cyclic or aromatic hydrocarbon chain, and SR′ moieties,wherein R′ is a C₁-C₅₀ linear, branched, cyclic or aromatic hydrocarbonchain, optionally substituted by C₁-C₁₂ linear, branched, cyclic oraromatic hydrocarbon groups, (said chains and/or groups can be)optionally substituted by COOH, F, and SR′; and [A-O]_(x)-A wherein A isa C₂-C₉ linear, branched, cyclic or aromatic hydrocarbon chain and x isan integer from 1 to 200; Z is a C₁-C₆ alkylene chain; M is selectedfrom H and C₁-C₂₀ linear, branched, cyclic or aromatic hydrocarbonchains; W is selected from H, ZPO₃M₂ and [V-N (K)]_(n)K, wherein V isselected from: a C₂-C₅₀ linear, branched, cyclic or aromatic hydrocarbonchain, optionally substituted by C₁-C₁₂ linear, branched, cyclic oraromatic groups, (which chains and/or groups can be) optionallysubstituted by OH, COOH, F, OR′, R²O[A-O]_(x)-wherein R² is a C₁-C₅₀linear, branched, cyclic or aromatic hydrocarbon chain, and SR′moieties; and from [A-O]_(x)-A wherein A is a C₂-C₉ linear, branched,cyclic or aromatic hydrocarbon chain and x is an integer from 1 to 200;K is ZPO₃M₂ or H and n is an integer from 0 to 200; and U is a moietyselected from OH and OR′ wherein R′ is as defined above; s is 1, inaqueous medium, having a pH of 8 or more, at a temperature of 0° C. orhigher.
 2. The process as claimed in claim 1 wherein the pH of thereaction medium is in the range of from 9-14.
 3. The process as claimedin claim 1 wherein X is selected from C₂-C₃₀ or [A-O]_(x)-A wherein A isC₂-C₆ and x is from 1-100 when U is OH.
 4. The process as claimed inclaim 1 wherein the individual moieties in the phosphonate reactionpartner are selected as follows: X is C₂-C₃₀ or [A-O]_(x)-A; V is C₂-C₃₀or [A-O] _(x)-A; wherein for both, X and V independently, A is C₂-C₆ andx is 1-100; R² is C₁-C₃₀; Z is C₁-C₃; M is H or C₁-C₆; and n is 1-00. 5.The process as claimed in claim 1 wherein the individual moieties in thephosphonate reaction partner are selected as follows: X is C₂-C₁₂ or[A-O] _(x)-A; V is C₁-C₁₂ or [A-O]_(x)-A; wherein for both, X and Vindependently, A is C₂-C₄ and x is 1-100; R ² is C₁-C_(12i) Z is C₁; Mis H or C₁-C₄ and n is 1-25.
 6. The process as claimed in claim 1wherein the precursor for U is; OH.
 7. The process as claimed in claim 2wherein the precursor for U is OR′.
 8. The process as claimed in claim 1wherein Y is selected from Cl, Br, I, HSO_(4r) NO₃, CH₃SO₃ and p-toluenesulfonate.